Tribological behaviour of Fe–28Al–5Cr alloy reinforced by TiC under acid environment

• TiC improves obviously the wear-resistance of Fe–28Al–5Cr alloy at H2SO4 solution.
• Wear rate of the composite with 50% TiC is 4–38 times lower than that of Fe–28Al–5Cr alloy.
• The reasons for low friction coefficients are due to the formation of FeS and hydrated silica.
• Wear resistance significantly increases with rising TiC amount.

Sliding wear behaviour of Fe–28Al–5Cr and its composites containing 15, 25, 35 and 50 wt% TiC was investigated against a Si3N4 ceramic ball in 1 mol/L H2SO4 solution. The wear rate and friction coefficient were significantly reduced by the addition of TiC. The main reason should be the load carrying role of hard TiC and the formed FeS and hydrated silica films becoming more and more stable with TiC content. The dominant wear mechanism of the Fe–28Al–5Cr alloy and the 15% composite is ploughing and corrosive wear, but that of the 25%, 35% and 50% composites is corrosive wear.